Suppressed production of nitric oxide as a cause of irregular constriction of gastric venules induced by thermal injury in rats.
Microcirculatory disturbance is a crucial step in development of gastric mucosal lesions. In this study we investigated the influence of nitric oxide (NO) on the irregular constriction of gastric venules observed in rats subjected to thermal injury. Male Wistar rats were anesthetized and a 30% full skin thickness dorsal burn was inflicted. Microvascular images in the submucosal layer and basal region of the gastric mucosa were obtained through an intravital microscope. Distribution of constitutive-type nitric oxide synthase (cNOS) was observed by the immunofluorescence method. Venule walls were basically smooth in the control group (no injury), whereas irregular constrictions tended to be observed in the 5-h group (5 h after thermal injury). Venule diameter was significantly smaller in the 5-h group. In the control group, cNOS-associated fluorescence was found on the venule endothelium, whereas it was almost negligible after thermal injury. A NO donor, 3-morpholinosydnonimine hydrochloride, simultaneously diminished the thermal injury-associated venule constriction and irregularity of venule walls. Therefore, the present study suggests that venule constriction, which is observed 5 h after thermal injury, is related to decreased NO production by endothelial cNOS and is a cause of irregularity of the venule walls.
Yoshida
M
M
Department of Surgery, Keio University School of Medicine, Tokyo, Japan.
Kurose
I
I
Wakabayashi
G
G
Hokari
R
R
Ishikawa
H
H
Otani
Y
Y
Shimazu
M
M
Miura
S
S
Ishii
H
H
Kitajima
M
M
D000818:Animals; D002056:Burns / Q000503:physiopathology*; D005753:Gastric Mucosa / Q000098:blood supply* / Q000187:drug effects; D008297:Male; D008981:Molsidomine / Q000031:analogs & derivatives / Q000494:pharmacology; D009569:Nitric Oxide / Q000096:biosynthesis / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology*; D014665:Vasodilator Agents / Q000494:pharmacology; D014699:Venules / Q000187:drug effects / Q000503:physiopathology
D014665:Vasodilator Agents; D009569:Nitric Oxide; C002385:linsidomine; D008981:Molsidomine; D019001:Nitric Oxide Synthase